Wafer transfer apparatus and substrate transfer apparatus

ABSTRACT

In the wafer transfer apparatus of the present invention, in a minimum transformed state where the robot arm is transformed such that a distance defined from the pivot axis to an arm portion, which is farthest in a radial direction relative to the pivot axis, is minimum, a minimum rotation radius R, as the distance defined from the pivot axis to the arm portion which is the farthest in the radial direction relative to the pivot axis, is set to exceed ½ of a length B in the forward and backward directions of the interface space, the length B corresponding to a length between the front wall and the rear wall of the interface space forming portion, and is further set to be equal to or less than a subtracted value (B−L 0 ) to be obtained by subtracting a distance L 0  in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis, from the length B in the forward and backward directions of the interface space (i.e., B/2&lt;R≦B−L 0 ). The present invention can provide a wafer transfer apparatus having a wafer transfer robot which can suppress scattering of dust as well as prevent occurrence of interference in the interior of the wafer transfer apparatus, and has a simple structure and can be readily controlled.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon the prior Japanese Patent Application No.2006-198771 filed on Jul. 20, 2006, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a wafer transfer apparatus for use insemiconductor processing equipment. The present invention also relatesto a substrate transfer apparatus for transferring a substrate in aninterface space, which is maintained in a predetermined atmosphere, of asubstrate processing equipment.

2. Description of the Related Art

FIG. 13 is a section showing a semiconductor processing equipment 1 ofthe related art, which is partly cut away. The semiconductor processingequipment 1 is configured to include a wafer processing apparatus 2 anda wafer transfer apparatus 3. The wafer transfer apparatus is anequipment front end module (EFEM). Spaces 9, 10 in the semiconductorprocessing equipment 1 are filled with a predetermined atmospheric gas,respectively. Specifically, the wafer processing apparatus 2 includes aprocessing space 10 which is filled with a predetermined atmosphericgas. Similarly, the wafer transfer apparatus 3 includes an interfacespace 9 which is filled with a predetermined atmospheric gas.

Semiconductor wafers 4, which are contained in each front openingunified pod (FOUP) 5 serving as a substrate container, are each carriedinto the semiconductor processing equipment 1. The wafer transferapparatus 3 includes an interface space forming portion 11, FOUP openers6, and a wafer carrying robot 7. A box 11 defines the interface space 9.The interface space 9 is maintained in a cleaned state due to a dustcollecting apparatus, such as a fan filter unit, which is fixed to thebox 11 (i.e., interface space forming portion). Each FOUP opener 6 isadapted to open and close doors respectively provided in the FOUP 5 andthe interface space forming portion 11. Each FOUP opener 6 can switch astate in which an internal space of each FOUP 5 and the interface space9 are in communication with each other and a state in which they areclosed to each other, by opening and closing each door. A wafer carryingrobot 7 is contained in the interface space 9 and is adapted to carryeach wafer 4 between each FOUP 5 and the wafer processing apparatus 2.

The wafer carrying robot 7 takes out each unprocessed wafer 4 from eachFOUP 5 in a state wherein the FOUP 5 is held by the wafer transferapparatus 3 and penetration of the outside air into the interface space9 is prevented. Then, the robot 7 carries the unprocessed wafer 4 takenfrom the FOUP 5, passes through the interface space 9, and positions thewafer 4 in the processing space 10 of the wafer processing apparatus 2.In addition, the wafer carrying robot 7 takes out each processed wafer 4from the processing space 10 of the wafer processing apparatus 2.Thereafter, the wafer carrying robot 7 carries the processed wafer 4taken out from the processing space 10, passes through the interfacespace 9, and places the wafer 4 again in the internal space of the FOUP5. By transferring each wafer 4 into the wafer processing apparatus 2 byusing each FOUP 5 and the wafer transfer apparatus 3 in this manner,attachment of dust floating in the atmosphere to the wafer 4 to beprocessed can be prevented. For example, such a technique is disclosedin JP No. 2003-45933 A.

FIG. 14 is a plan view of a semiconductor processing equipment 1A of afirst related art, which is partly cut away. A robot arm 14 of the wafercarrying robot 7 of the first related art includes a first link member15 a which is connected with a base 18 and can be pivoted about a pivotaxis A0 set at the base 18, a second link member 15 b which is connectedwith the first link member 15 a and can be angularly displaced about afirst joint axis A1 set at the first link member 15 a, and a third linkmember 15 c which is connected with the second link member 15 b and canbe angularly displaced about a second joint axis A2 set at the secondlink member 15 b. The third link member 15 c has a robot hand 12provided at its distal end.

The wafer carrying robot 7 is set such that a minimum rotation region17, which is required for the robot 7 to perform one rotation about thebase 18 in a state wherein each link member 15 a to 15 c is angularlydisplaced relative to one another to make the smallest form of the robot7, can be contained in the interface space 9. In other words, a minimumrotation radius R of the robot is set smaller than a half (½) of alength B (FIG. 15) in forward and backward directions of the interfacespace 9. In addition, a distance L11 between the pivot axis A0 and thefirst joint axis A1 and a distance L12 between the first joint axis A1and the second joint axis A2 are set to be the same.

In order to enable the wafer transfer apparatus 3 to perform attachingand detaching operations of each FOUP 5 relative to the wafer transferapparatus 3 and a transferring operation of each wafer 4 to and fromeach FOUP 5 held by the wafer transfer apparatus 3, at the same time,there is a case where three or four FOUP openers 6 are provided in thesystem. In such a case, the wafer carrying robot 7 of the first relatedart as described above can not reach, in some cases, the FOUP 5 that isfarthest from the base 15, by using its hand 12. However, if attemptingto extend the length of each link member in order to enlarge a movableregion of the robot 7, the robot arm 14 may interfere with the interfacespace forming portion 11 and may be advanced into a robot invasionrestricted region.

FIG. 15 is a plan view showing a semiconductor processing equipment 1Bof a second related art, which is partly cut away. As shown in FIG. 15,in the second related art, in order to make it possible to transferwafers 4 of all of the FOUPs 5, the wafer carrying robot 7 includes arobot main body 13 having a robot arm 14 and a running means 12 which isadapted to drive the robot main body 13 to run in directions Y parallelto the row of the FOUPs 5.

In the second related art, the running means 12 for driving the robotmain body 13 to run is located in the interface space 9. The runningmeans 12 can be achieved by employing a direct acting mechanism. It isdifficult, however, to seal the direct acting mechanism against dust tobe generated in a driving portion, as compared with the case of arotation driving mechanism. Therefore, due to dust to be generated bythe running means, cleanliness in the interface space 9 may tend to bedegraded.

In the case of driving the robot main body 13 to run at a high speed,since the robot main body 13 is of a large size, power to be spent forthe running operation of the robot main body 13 should be increased,with respect to the running means 12. In addition, the running means 12should also be of a large size in order to support the robot main body13, thus making it difficult to downsize the robot 7 and reduce theweight thereof. Because the running means 12 is of a large size, it isdifficult to exchange the running means 12 in the case of occurrence ofmalfunctioning in the running means 12. In addition, the provision ofsuch a running means 12 leads to further increase of the productioncost.

Increase of the number of the link members of the robot arm 14 in orderto enlarge the movable region of the wafer carrying robot 7 can make therunning means 12 as disclosed in the second related art be unnecessary.However, in the case of increasing the number of the link members of therobot arm 14, the robot structure should be complicated so much.Additionally, the increase of the link members increases in turnredundancy of the robot, as such control of the robot arm 14 may tend tobe difficult. For example, in regard to the wafer transfer, a teachingoperation for teaching transformed states of the robot arm may befurther complicated.

Such problems may occur in other apparatuses than the wafer transferapparatus. Specifically, in the case of substrate transfer apparatuseseach provided with a substrate carrying robot for carrying eachsubstrate in the interface space which is maintained in a predeterminedatmosphere, the same problems as those describe above may occur.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a wafertransfer apparatus having a wafer transfer robot which can suppressscattering of dust and prevent occurrence of interference in theinterior of the wafer transfer apparatus, and has a simple structure andcan be readily controlled.

Another object of the present invention is to provide a substratetransfer apparatus having a substrate transfer robot which can suppressscattering of dust and prevent occurrence of interference in theinterior of the substrate transfer apparatus, and has a simple structureand can be readily controlled.

The present invention is a wafer transfer apparatus for transferring asemiconductor wafer which is carried while being contained in asubstrate container, relative to a wafer processing apparatus forsemiconductor processing, comprising: an interface space forming portiondefining an interface space which is to be filled with a preconditionedatmospheric gas, the interface space forming portion having a front walland a rear wall which are arranged at a predetermined interval inforward and backward directions, the front wall having a front openingformed therein, and the rear wall having a rear opening formed therein;a FOUP opener configured to open and close the substrate containerlocated adjacent to the interface space and the front opening of theinterface space forming portion; and a wafer carrying robot located inthe interface space and configured to carry the semiconductor waferbetween the front opening and the rear opening. The wafer carrying robotincludes: a base which is fixed to the interface space forming portionand at which a predetermined pivot axis is set; a robot arm having aproximal end and a distal end, the robot arm including a plurality oflink members connected with one another in succession in a directionfrom the proximal end to the distal end, the proximal end beingconnected with the base, the distal end being provided with a robot handfor holding the wafer, the robot arm being configured to be angularlydisplaced about the pivot axis; and a drive unit configured to driveeach of the link members of the robot arm so that the link members areangularly displaced, individually, about each corresponding axis. In aminimum transformed state where the robot arm is transformed such that adistance defined from the pivot axis to an arm portion which is farthestin a radial direction relative to the pivot axis is minimum, a minimumrotation radius R, as the distance defined from the pivot axis to thearm portion which is the farthest in the radial direction relative tothe pivot axis, is set to exceed ½ of a length B in the forward andbackward directions of the interface space, the length B correspondingto a length between the front wall and the rear wall of the interfacespace forming portion, and is further set to be equal to or less than asubtracted value (B−L0) to be obtained by subtracting a distance L0 inthe forward and backward directions from the rear wall of the interfacespace forming portion to the pivot axis, from the length B in theforward and backward directions of the interface space (i.e.,B/2<R≦B−L0).

According to this invention the substrate container is located whilebeing adjacent to the front opening of the interface space formingportion. In this state, the FOUP opener opens the substrate containertogether with the front opening so as to make the internal space of thesubstrate container and the interface space be in communication witheach other. The wafer carrying robot takes out an unprocessed wafer fromthe substrate container, carries the unprocessed wafer into theinterface space from the front opening, passes through the interfacespace, and carries the wafer into the wafer processing apparatus throughthe rear opening. Alternatively, the wafer carrying robot takes out aprocessed wafer which has been processed in the wafer processingapparatus, carries it into the interface space from the rear opening,passes through the interface space, and carries the wafer into thesubstrate container through the front opening.

In the interface space, the atmospheric gas is controlled. Thus, whencarrying the unprocessed wafer into the wafer processing apparatus fromthe substrate container, or when carrying the processed wafer into thesubstrate container from the wafer processing apparatus, attachment ofdust floating in the atmosphere to the wafer can be prevented, therebyenhancing the yield of the wafer to be processed.

In the present invention, the minimum rotation radius R of the robot armcan be increased, as compared to the first and second related artsdescribed above, by setting the minimum rotation radius R of the robotarm at a value greater than ½ of the length B in the forward andbackward directions of the interface space. In addition, with theminimum rotation radius R of the robot arm set to be equal to or lessthan the subtracted value (B−L0), a gap can be securely provided betweenthe robot arm in its minimum transformed state and the front wall, thuspreventing interference of the robot arm with the front wall. In thismanner, a robot hand which is a distal end of the robot arm can belocated on both sides in the left and right directions, orthogonally toboth of the forward and backward directions and the pivot axialdirection extending along the pivot axis, with respect to a referenceline defined to include the pivot axis and extend in the forward andbackward directions. By driving the robot arm to be operated in anoperational range excluding an interferential operational range in whichthe robot arm would interfere with the rear wall, interference with therear wall can also be prevented. Namely, with the restriction of theangularly displacing operational range of the robot arm to be less than360 degrees, for example, about 180 degrees, interference of the robotarm with the rear wall can be prevented.

Thus, even though the length B in the forward and backward directions ofthe interface space is significantly small, the length of each linkmember of the robot arm can be increased, while preventing theinterference of the robot arm with the front wall, so as to enlarge theoperational range of the robot arm. In particular, the operational rangeof the robot arm can be enlarged with respect to the left and rightdirections orthogonal to both the forward and backward directions andthe pivot axial direction. For example, the distance L0 in the forwardand backward directions from the rear wall to the pivot axis A0 is setto be less than ⅕ of the length B in the forward and backward directionsof the interface space (i.e., L0<B/5).

By increasing the link length of each link member of the robot arm, theoperational range of the robot arm can be increased with respect to theleft and right directions. Thus, as compared with the second relatedart, there is no need for a running means for driving the robot to runin the left and right directions, and a direct acting mechanism can beeliminated. Accordingly, dust to be generated by such a direct actingmechanism can be avoided, as such degradation of the cleanliness in theinterface space can be prevented. In addition, the elimination of therunning means leads to downsizing and weight reduction of the robot.

Also, by increasing the link length of each link member of the robotarm, it becomes possible to have the robot hand reach a predeterminedposition in a wider range. Additionally, necessity for increasing thenumber of the link members can be avoided, thus simplifying the robotstructure. Furthermore, the redundancy of the robot can be reduced, andthe control and teaching concerning transformed states for the robot armcan be simplified, thereby reducing possibility that the robot arm wouldcollide with the interface space forming portion.

As described above, in this invention, scattering of dust can besuppressed due to elimination of the running means, as well asinterference in the wafer transfer apparatus can be avoided. Therefore,a wafer transfer apparatus including a wafer carrying robot, which canachieve more simplified structure and control, can be provided.

Preferably, the minimum rotation radius R is set to be equal to or lessthan an allowable length (B−L0−E) to be obtained by subtracting thedistance L0 in the forward and backward directions from the rear wall ofthe interface space forming portion to the pivot axis and a length E ofa robot invasion restricted region, which is set for the FOUP opener andis measured from the front wall in the forward and backward directionstoward the rear wall, from the length B in the forward and backwarddirections of the interface space (i.e., R≦B−L0−E).

According to this invention, by setting the minimum rotation radius R tobe equal to or less than the allowable length (B−L0−E), even in the casewhere the robot arm approaches nearest relative to the front wall,entering of any portion of the robot arm into a movable region of theFOUP opener can be prevented. Therefore, interference of the robot armwith the FOUP opener can be prevented, regardless of the movable regionor state of the FOUP opener. Thereby, defective operations of the wafertransfer apparatus can be eliminated.

Preferably, the robot arm includes: a first link member which isconnected at its one end with the base, configured to be angularlydisplaced about the pivot axis, and at which a first joint axis is setin parallel to the pivot axis; a second link member which is connectedat its one end with an other end of the first link member, configured tobe angularly displaced about the first joint axis, and at which a secondpivot axis is set in parallel to the pivot axis; and a third link memberwhich is connected at its one end with an other end of the second linkmember, configured to be angularly displaced about the second jointaxis, and includes the robot hand at an other end of the third linkmember for holding the wafer. A first link distance L1 defined as adistance from the pivot axis to an end of the first link member, whichis farthest in a radial direction toward the first joint axis relativeto the pivot axis, is set to exceed ½ of the allowable length (B−L0−E)and to be equal to or less than the allowable length (B−L0−E) (i.e.,((B−L0−E)/2<L1≦B−L0−E).

According to this invention, the first link distance L1 is set to exceed½ of the allowable length (B−L0−E) and to be equal to or less than theallowable length (B−L0−E). Consequently, even in the case where thefirst link member approaches nearest relative to the front wall,entering of any portion of the first link member into a movable regionof the FOUP opener can be prevented. Thus, the other end of the firstlink member can be moved on both sides in the left and right directionsrelative to the pivot axis while preventing its interference with thefront wall. By increasing the first link distance L1, as large aspossible, provided that it is set to be equal to or less than theallowable length (B−L0−E), interference of the first link member withthe front wall as well as with the FOUP opener can be prevented, and theother end of the first link member can be moved into a significantly farposition in both of the left and right directions with respect to thepivot axis, thereby to enlarge the operational range of the first linkmember. Namely, interference of the first link member with the frontwall as well as with the FOUP opener can be prevented, while increasingthe link length of the first link member. Additionally, due torestriction of the angularly displacing operational range of the robotarm to be less than 360 degrees, for example, about 180 degrees,interference of the first link member with the rear wall can also beprevented. Due to the increase of the length of the first link member,the second and third link members can be located in farther positionsfrom the pivot axis in the left and right directions, thus enlarging themovable region of the robot in the left and right directions.

Preferably, a first axis-to-axis distance L11 from the pivot axis to thefirst joint axis and a second axis-to-axis distance L12 from the firstjoint axis to the second joint axis are set to be equal to each other. Asecond link distance L12 defined as a distance from the second jointaxis to an end of the second link member, which is farthest in adirection toward the first joint axis relative to the second joint axis,is set to exceed ½ of the allowable length (B−L0−E) and to be equal toor less than the allowable length (B−L0−E).

According to this invention, in a state where the second link member isoverlapped with the first link member with respect to the pivot axialdirection such that the pivot axis is coincident with the second jointaxis, the distance from the second joint axis to the end portion of thesecond link member, which is the farthest from the pivot axis, is set tobe equal to or less than the allowable length (B−L0−E). Accordingly, inthe state wherein the pivot axis is coincident with the second jointaxis, entering of any portion of the second link member into the movableregion of the FOUP opener can be prevented. Additionally, by increasingthe second link distance L2, as large as possible, provided that it isset to be equal to or less than the allowable length (B−L0−E),interference of the second link member with the front wall as well aswith the FOUP opener can be prevented, and the other end of the secondlink member can be moved into a significantly far position in both ofthe left and right directions with respect to the pivot axis, thereby toenlarge the operational range of the second link member. Namely, bydriving the robot arm to take its minimum transformed state byoverlapping the first link member with the second link member,interference of the second link member with the front wall as well aswith the FOUP opener can be prevented, while increasing the link lengthof the second link member. This increase of the length of the secondlink member enables the third link member to be located in a positionfarther from the pivot axis in the left and right directions, therebyenlarging the movable region of the robot in the left and rightdirections.

By setting the first axis-to-axis distance L11 and the secondaxis-to-axis distance L12 to be the same, and by setting an angularlydisplacing amount of the first link member about the pivot axis to betwice the angularly displacing amount of the second link member aboutthe first angular displacement axis, the other end of the second linkmember can be moved in parallel to the left and right directions, thusfacilitating control of the arm body. It should be noted that the term“the same” is intended to imply substantially the same state, as such itincludes the same state and substantially the same state.

Preferably, a third link distance L3 defined as a distance from thesecond joint axis to an end of the third link member or a portion of thewafer, which is farthest in a radial direction relative to the secondjoint axis, is set to exceed ½ of the allowable length (B−L0−E) and tobe equal to or less than the allowable length (B−L0−E).

According to this invention, in a state wherein the first to third linkmembers are overlapped such that the pivot axis is coincident with thesecond joint axis, the distance from the second joint axis to the endportion of the third link member, which is the farthest from the pivotaxis, is less than the allowable length (B−L0−E). Accordingly, in thestate where the pivot axis is coincident with the second pivot axis,entering of any portion of the third link member or any portion of thewafer held by the third link member into the movable region of the FOUPopener can be prevented. In addition, by increasing the third linkdistance L3, as large as possible, provided that it is set to be equalto or less than the allowable length (B−L0−E), interference of the thirdlink member with the front wall as well as with the FOUP opener can beprevented, and the other end of the third link member can be moved intoa significantly far position in both of the left and right directionswith respect to the pivot axis, thereby to enlarge the operational rangeof the third link member. Namely, by operating the robot arm to take itsminimum transformed state by driving the first to third link members tobe overlapped with one another, interference of the third link memberwith the front wall as well as with the FOUP opener can be prevented,while increasing the link length of the third link member. Due to suchincrease of the length of the third link member, the wafer held by thethird link member can be located in a farther position from the pivotaxis in the left and right directions, thereby to extend the movableregion of the robot in the left and right directions.

Preferably, the first link distance L1, the second link distance L2 andthe third link distance L3 are respectively set to be equal to theallowable length (B−L0−E).

According to this invention, the first to third link distances L1 to L3are each set to be the same as the allowable length (B−L0−E).Consequently, when the robot arm is in the minimum transformed state,contact of each link member with the front wall as well as with the FOUPopener can be prevented. The term “the same” is intended to implysubstantially the same state, as such it includes the same state andsubstantially the same state. Since each link member is set to be aslarge as possible while preventing interference, the operational rangeof the robot arm with respect to the left and right directions can beincreased. Thus, even in the case where the front opening and the rearopening are formed away from each other in the left and rightdirections, this robot arm can perform both carrying in and carrying outoperations for each wafer. Namely, in the case where the robot arm takesits minimum transformed state, contact of each link member with thefront wall as well as with the FOUP opener can be prevented. Inaddition, the length of each link member can be increased as large aspossible, the operational range of the robot arm can be increased somuch. Therefore, even in the case where the front opening and the rearopening are provided in positions spaced away relative to each other inthe forward and backward directions, the robot arm can perform thecarrying in and carrying out operations for each wafer.

Preferably, the front opening includes four openings which are formed inthe interface space forming portion, the four openings being arranged inleft and right directions orthogonal to both the forward and backwarddirections and a direction of the pivot axis. The FOUP opener includesfour openers which are provided in order to open and close the fouropenings, respectively.

According to this invention, even in the case where the length B in theforward and backward directions of the interface space is relativelysmall as described above, the operational range in the left and rightdirections of the robot arm can be significantly increased. Thus, evenin the case where the four FOUP openers are provided, carrying in andcarrying out operations for each wafer between the substrate containerattached to each FOUP opener and the wafer processing apparatus can besecured, without providing any additional running means for the robot,and without increasing the number of link members of the robot arm.Since the four FOUP openers are provided, the carrying, attachment anddetachment operations of each substrate container relative to the wafertransfer apparatus and the transfer operation of each wafer contained inthe substrate container held by the wafer transfer apparatus can becarried out, in parallel, thereby enhancing the working efficiency.

The present invention is a substrate transfer apparatus for transferringa substrate, in an interface space filled with a preconditionedatmospheric gas, relative to a substrate processing apparatus forprocessing the substrate, comprising:

an interface space forming portion defining the interface space, theinterface space forming portion having a front wall and a rear wallwhich are arranged in predetermined forward and backward directions atan interval, the front wall having a first transfer port formed therein,and the rear wall having a second transfer port formed therein; anopening and closing unit configured to open and close the first transferport of the interface space forming portion; and a substrate carryingrobot located in the interface space and configured to carry thesubstrate between the first transfer port and the second transfer port.The substrate carrying robot includes: a base which is fixed to theinterface space forming portion and at which a predetermined pivot axisis set; a first link member which is connected at its one end with thebase, configured to be angularly displaced about the pivot axis, and atwhich a first joint axis is set in parallel to the pivot axis; a secondlink member which is connected at its one end with an other end of thefirst link member, configured to be angularly displaced about the firstjoint axis, and at which a second pivot axis is set in parallel to thepivot axis; a third link member which is connected at its one end withan other end of the second link member, configured to be angularlydisplaced about the second joint axis, and includes a robot hand at another end thereof for holding the substrate; and a drive unit configuredto drive each of the link members so that the link members are angularlydisplaced, individually, about each corresponding axis. The pivot axisis located nearer the rear wall than the front wall in the forward andbackward directions. A first link distance L1 defined as a distance fromthe pivot axis to an end of the first link member, which is farthest ina radial direction toward the first joint axis relative to the pivotaxis, is set to exceed ½ of a length B in the forward and backwarddirections of the interface space, the length B corresponding to alength between the front wall and the rear wall of the interface spaceforming portion, and is further set to be equal to or less than asubtracted value (B−L0) to be obtained by subtracting a distance L0 inthe forward and backward directions from the rear wall of the interfacespace forming portion to the pivot axis, from the length B in theforward and backward directions of the interface space (i.e.,B/2<L1≦B−L0).

According to this invention, the minimum rotation radius R of the robotarm can be increased, as compared with the first and second relatedarts, by setting the minimum rotation radius R of the robot arm toexceed ½ of the length B in the forward and backward directions of theready arm. In addition, by setting the minimum rotation radius R of therobot arm to be equal to or less than the aforementioned subtractedvalue (B−L0), a gap can be securely provided between the robot arm inits minimum transformed state and the front wall, thus preventinginterference of the robot arm with the front wall. With the restrictionof the angularly displacing operational range of the robot arm to beless than 360 degrees, for example, about 180 degrees, interference ofthe robot arm with the rear wall can also be prevented.

Consequently, even in the case where the length B in the forward andbackward directions of the interface space is relatively small, the linklength of each link member of the robot arm can be increased, whilepreventing interference between the robot arm and the front wall.Accordingly, the operational range of the robot arm can be increased. Inparticular, the operational range of the robot arm can be increased,with respect to the left and right directions orthogonal to both of theforward and backward directions and the pivot axial direction. Thus, therobot arm can be adequately operated without requiring any additionalrunning means and/or unduely increasing the number of the link members.

According to the substrate transfer apparatus of the present invention,there is no need for a running means for driving the robot to run in theleft and right directions, and dust to be generated by such a runningmeans can be avoided, thereby preventing degradation of the cleanlinessin the interface space. In addition, the number of the link membersrequired for the robot arm can be reduced, as such simplifying the robotstructure. Moreover, the redundancy of the robot can be decreased,thereby to reduce the possibility that the robot arm would collide withthe interface space forming portion.

As stated above, according to the present invention, scattering of dustcan be suppressed due to the elimination of the running means, andoccurrence of interference in the substrate transfer apparatus can beavoided due to the control of increase of the link members. Therefore,the substrate transfer apparatus comprising the substrate transfer robotwhich can simplify the structure and control can be provided. It shouldbe appreciated that the substrate transfer apparatus can be applied toother substrates than the semiconductor wafer, and that these substratesmay include those to be processed in a preset controlled space, forexample, glass substrates or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent from the following description takenin connection with the accompanying drawings, in which:

FIG. 1 is a plan view showing a part of semiconductor processingequipment 20 comprising a wafer transfer apparatus 23 which is a firstembodiment of the present invention;

FIG. 2 is a section showing the semiconductor processing equipment 20,which is partly cut away;

FIG. 3 is a plan view showing a wafer transfer apparatus, which issimplified, for explaining a length of each link member 41 a to 41 c;

FIG. 4 is a diagram showing a carrying operation, which is simplified,for carrying a wafer 24 contained in a first FOUP 25 a to an aligner 56;

FIG. 5 is a diagram showing a carrying operation, which is simplified,for carrying the wafer 24 supported by the aligner 56 to a processingspace 30;

FIG. 6 is a diagram showing a carrying operation, which is simplified,for carrying the wafer 24 located in the processing space 30 to thefirst FOUP 25 a;

FIG. 7 is a diagram showing a state in which the wafer 24 is located inits receiving and transferring positions of the embodiment according tothe present invention;

FIG. 8 is a plan view showing the wafer transfer apparatus in the casethat there are three FOUP openers;

FIG. 9 is a plan view showing the wafer transfer apparatus in the casethat there are two FOUP openers;

FIG. 10 is a plan view showing a wafer transfer apparatus 23A, which isa second embodiment of the present invention and is somewhat simplified;

FIG. 11 is a plan view showing a wafer transfer apparatus 23B, which isa third embodiment of the present invention and is somewhat simplified;

FIG. 12 is a plan view showing a semiconductor processing apparatus 20Cwhich is a fourth embodiment of the present invention;

FIG. 13 is a section showing a semiconductor processing equipment 1 ofthe related art, which is partly cut away;

FIG. 14 is a plan view showing a semiconductor processing equipment 1Aof a first related art, which is partly cut away;

FIG. 15 is a plan view showing a semiconductor processing equipment 1Bof a second related art, which is partly cut away.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIGS. 1 and 2, the semiconductor processing equipment 20according to the first embodiment of the present invention provides apredetermined process to each semiconductor wafer 24 which is asubstrate to be processed. For example, as the process to be provided tothe semiconductor wafer 24, various processes including heating,impurity doping, film forming, lithography, washing or flattening may beincluded. In addition, the semiconductor processing equipment 20 mayperform other substrate processes than those described above.

The semiconductor processing equipment 20 performs the aforementionedprocesses in a processing space 30 filled with an atmospheric gas havingadequate cleanliness. Wafers 24 are carried into the semiconductorprocessing equipment 20 while being contained in large numbers ina-substrate container referred to as a front opening unified pod (FOUP)25. Each FOUP 25 is intended to serve as a mini-environmental substratecontainer configured to provide a clean environment for the locallycleaning technique.

Each FOUP 25 is configured to include a FOUP main body 60 which is acontainer main body in which the wafers 24 are contained, and aFOUP-side door 61 as a container-side door which can be attached to anddetached from the FOUP main body 60. The FOUP main body 60 is formedinto a generally box-like shape which opens in one direction, and inwhich a FOUP internal space 34 is defined as a space for containing thewafers. Due to attachment of the FOUP-side door 61 to the FOUP main body60, the FOUP internal space 34 is closed air-tightly against an externalspace 33, as such invasion of contaminant, such as dust particles, fromthe external space 33 into the FOUP internal space 34 can be prevented.Contrary, due to removal of the FOUP-side door 61 from the FOUP mainbody 60, the wafer 24 can be contained in the FOUP internal space 34, aswell as the wafers 24 contained in the FOUP internal space 34 can betaken out therefrom. Each FOUP 25 contains a plurality of wafers 24therein in a stacked state in upward and downward directions Z. Eachwafer 24 contained in the FOUP 25 is arranged at an equal interval inthe upward and downward directions Z, with one face in the thicknessdirection extending horizontally.

The semiconductor processing equipment 20 is configured to include awafer processing apparatus 22 and a wafer transfer apparatus 23. Thesemiconductor processing equipment 20 is prescribed, for example, in theSEMI (Semiconductor Equipment and Materials International) standard. Inthis case, for example, each FOUP 25 and a FOUP opener 26 adapted toopen and close the FOUP 25 follow the specifications, including E47.1,E15.1, E57, E62, E63, E84, of the SEMI standard. It should be noted thateven though the construction of the semiconductor processing equipmentdoes not fall within the SEMI standard, such construction may also beincluded in this embodiment.

The wafer processing apparatus 22 provides the predetermined processdescribed above to each wafer 24 in the processing space 30. In additionto a processing apparatus main body adapted to provide a process to eachwafer 24, the wafer processing apparatus 22 includes a processing spaceforming portion defining the processing space 30, a carrier adapted tocarry each wafer 24 in the processing space 30, and a controller adaptedto control the atmospheric gas filled in the processing space 30. Thecontroller can be achieved by a fan filter unit or the like.

The wafer transfer apparatus 23 is configured to take out eachunprocessed wafer 24 from each FOUP 25 and supply it into the waferprocessing apparatus 22, as well as configured to take out eachprocessed wafer 24 from the wafer processing apparatus 22 and place itin each FOUP 25. The wafer transfer apparatus 23 is an equipment frontend module (EFEM). The wafer transfer apparatus 23 serves as aninterface, which is adapted to transfer each wafer 24 between each FOUP25 and the wafer processing apparatus 22. In this case, the wafer 24passes through an interface space 29 filled with a predeterminedatmospheric gas and having high cleanliness, during its movement betweeneach FOUP internal space 34 and the processing space 30 of the waferprocessing apparatus 22.

The interface space 29 is a closed space to which contamination controlis provided and in which the number of floating micro-particles in theair is controlled to be less than a limited level of cleanliness. Inaddition, the interface space 29 is a space in which environmentalconditions, such as temperature, humidity and pressure, are alsocontrolled as needed. In this embodiment, the cleanliness of processingspace 30 and interface space 29 is maintained such that it does not havenegative impact on the process for each wafer 24. For example, as thecleanliness, the CLASS1 prescribed in the international organization forstandardization (ISO) is employed.

The wafer transfer apparatus 23 includes an interface space formingportion 28 defining the interface space 29, the wafer carrying robot 27which is located in the interface space 29 and capable of carrying eachwafer, FOUP openers 26 which serve as opening and closing apparatuseseach adapted to open and close each corresponding FOUP 25, and aninterface space controller 100 adapted to control an atmospheric gasfilled in the interface space 29. In this embodiment, the wafer transferapparatus 23 further includes an aligner 56 adapted to align a directionof each wafer 24 held in a predetermined position.

The interface space forming portion 28 surrounds the interface space 29to prevent the outside air from entering the interface space 29 from theexternal space 33. In the interface space forming portion 28, carrierelements required for carrying each wafer 24 are fixed respectively. Inthis embodiment, four FOUP openers 26 a, 26 b, 26 c, 26 d, one wafertransfer robot 27, and one aligner 56 are fixed in the interface spaceforming portion 28, respectively.

The interface space forming portion 28 is formed into a rectangularparallelepiped box-like shape, so as to form a rectangularparallelepiped interface space 29. The interface space forming portion28 includes a front wall 110 and a rear wall 111 which are arranged toprovide a predetermined interval therebetween in forward and backwarddirections X. The front wall 110 serves as a partition for separatingthe interface space 29 from the external space 33 existing in a positionon the side in the forward direction X1 relative to the interface space29. The rear wall 111 serves as a partition for separating the interfacespace 29 from the processing space 30. Accordingly, the read space 29 islocated on the side in the backward direction X2 relative to theexternal space 33 and is defined on the side in the forward direction X1relative to the processing space 30.

The interface space forming portion 28 includes two side walls 112, 113which are arranged to provide an interval in the left and rightdirections Y. In addition, the interface space forming portion 28includes a ceiling wall 114 and a bottom wall 115 which are arranged todefine an interval in the upward and downward directions Z. These walls110 to 115 of the interface space forming portion 28 are each formedinto a plate-like shape.

In this embodiment, the forward and backward directions X and the leftand right directions Y are predefined directions, respectively. Theforward and backward directions X and the left and right directions Yare orthogonal to the upward and downward directions Z, respectively,and extend horizontally to be orthogonal to each other. The backwarddirection X2 of the forward and backward directions X is a direction inwhich each wafer 24 contained in each FOUP 25 is carried into theprocessing space 30. The forward direction X1 of the forward andbackward directions X is a direction in which each wafer 24 contained inthe processing space 30 is carried back into each corresponding FOUP 25.

The first side wall 112 connects one ends together in the left and rightdirections of the front wall 110 and rear wall 111. The second side wall113 connects the other ends together in the left and right directions ofthe front wall 110 and rear wall 111. The ceiling wall 114 connects topends of the front wall 110, rear wall 111, first side wall 112 andsecond side wall 113, respectively. The bottom wall 115 connects bottomends of the front wall 110, rear wall 111, first side wall 112 andsecond side wall 113, respectively.

The interface space 29 is closed in the forward and backward directionsX by the front wall 110 and the rear wall 111. In addition, theinterface space 29 is closed in the left and right directions Y by thefirst side wall 112 and the second side wall 113. Furthermore, theinterface space 29 is closed in the upward and downward directions Z bythe ceiling wall 114 and the bottom wall 115. In this manner, theinterface space 29 is defined. The interface space forming portion 28has a sectional shape vertical to the upward and downward directions Zsuch that the left and right directions Y corresponds to itslongitudinal direction and the forward and backward directions Xcorresponds to its width direction, so as to be defined as a squareframe. Accordingly, the interface space 29 defines an oblong space thatis longer in the left and right directions Y than in the forward andbackward directions X.

In the front wall 110, front openings 120 are formed, each extendingthrough the wall in the forward and backward directions X, i.e., in thethickness direction. Each front opening 120 is formed to enable eachwafer 24 to pass therethrough. Specifically, due to the wafer carryingrobot 27, each wafer 24 is moved to pass through each correspondingfront opening 120, and carried in the backward direction X2 relative tothe front wall 110, thus inserted into the interface space 29 from theexternal space 33. Alternatively, due to the wafer carrying robot 27,each wafer 24 is moved to pass through each corresponding front opening120, and carried in the forward direction X1 relative to the front wall110, thus discharged into the external space 33 from the interface space29. In this embodiment, four front openings 120 are provided such thatthe respective front openings 120 are arranged in the left and rightdirections Y.

In the rear wall 111, rear openings 121 are formed, each extendingthrough the wall in the forward and backward directions X, i.e., in thethickness direction. Each rear opening 121 is formed to enable eachwafer 24 to pass therethrough. Again, due to the wafer carrying robot27, each wafer 24 is moved to pass through each corresponding rearopening 121, and carried in the backward direction X2 relative to therear wall 111, thus inserted into the processing space 30 from theinterface space 29. Alternatively, due to the wafer carrying robot 27,each wafer 24 is moved to pass through each corresponding rear opening121, and carried in the forward direction X1 relative to the rear wall111, thus inserted into the interface space 29 from the processing space30. In this embodiment, two rear openings 121 are provided such that therespective rear openings 121 are arranged in the left and rightdirections Y.

Te FOUP openers 26 a to 26 d are each configured to include a front faceplate 101, an opener-side door 65, a FOUP supporting portion 31, and adoor opening and closing mechanism 109. The FOUP openers 26 a to 26 dare arranged at an equal interval in the left and right directions Y.The FOUP openers 26 a to 26 d are located on the side in the forwarddirection X1 relative to the interface space forming portion 28. EachFOUP opener 26 a to 26 d also serves as a substrate container settingtable for setting each corresponding FOUP, i.e., the substratecontainer. Accordingly, each FOUP opener 26 a to 26 d is adapted to workas the substrate container setting table for supporting at least eachcorresponding FOUR Each front face plate 101 constitutes a part of thefront wall 110 of the interface space forming portion 28. The front faceplate 101 of each FOUP opener 26 a to 26 d is a plate-like or frame-likemember defining each front opening 120 described above therein, andconstitutes the front wall 110 while being fixed to the remainder of thefront wall 110. To the front opening 120 defined in each front faceplate 101, the FOUP-side door 61 is provided such that it can passtherethrough in the forward and backward directions X.

Each opener-side door 65 is adapted to open and close each correspondingfront opening 120. Each FOUP supporting portion 31 is located in theexternal space 33 on the side in the forward direction X1 relative tothe interface space 29 and adapted to support each FOUP 25 from below.Each FOUP 25 is formed such that it can be located in an attachingposition, which is set by each corresponding FOUP supporting portion 31,while being supported by the FOUP supporting portion 31. Hereinafter,the FOUPs supported correspondingly to the first to fourth FOUP openers26 a to 26 d will be referred to as first to fourth FOUPs 25 a to 25 d,respectively. However, when it is not necessary to distinguish them asthe first to fourth FOUPs 25 a to 25 d, they will be merely referred toas the FOUP(s) 25 or each FOUP 25.

In a state wherein the FOUP 25 is located in an attaching position, theopening 60 a of the FOUP main body 60 is in contact with all thecircumference of the opening portion 101 a of the front face plate 101.In the state located in the attaching position, the FOUP door 61 isopposed from the external space 33 to the opener-side door 65 closingthe front opening 120.

Each door opening and closing mechanism 109 is adapted to open and closeeach corresponding opener-side door 65 and FOUP-side door 61 while eachcorresponding FOUP 25 is located in the attaching position. When thedoor opening and closing mechanism 109 holds directly or indirectly theopener-side door 65 and the FOUP-side door 61, moves them from eachopening 60 a, 101 a downward and in the backward direction X2, and thenmoves them to a release position set in the interface space 29, the FOUPinternal space 34 and the interface space 29 are in communication witheach other. Contrary, when the door opening and closing mechanism 109attaches the opener-side door 65 and the FOUP-side door 61 to theopenings 60 a, 101 a, respectively, the communication between the FOUPinternal space 34 and the interface space 29 is shut off.

In the state wherein the FOUP 25 is located in the attaching position,the opening 60 a of the FOUP main body 60 and the opening 101 a of thefront face plate 101 are in contact with each other over all of theirperipheries. Accordingly, in the state wherein the FOUP 25 is located inthe attaching position, even when the opener-side door 65 and theFOUP-side door 61 are removed from the respective openings 60 a, 101 adue to the door opening and closing mechanism 109, entering of theoutside air into the FOUP internal space 34 and the interface space 29can be prevented.

The respective FOUP openers 26 a to 26 d are arranged in the left andright directions Y, and configured to operate individually. FIG. 1illustrates a state wherein the first FOUP opener 26 a positioned on themost left side (in the drawing) opens the corresponding front opening120. In addition, FIG. 1 shows a state wherein the FOUP openers 26 b to26 d other than the first FOUP opener 26 a close the corresponding frontopenings 120, respectively.

For each FOUP opener 26 a to 26 d, a movable region 108 is set, in whicheach door 61, 65 can be moved to the release position, due to the dooropening and closing mechanism 109. The movable region 108 of each FOUPopener 26 a to 26 d is set in the interface space 29 and is defined nearthe front wall 110 in the interface space 29.

The wafer transfer robot 27, in this embodiment, is achieved by ahorizontal articulated robot of a selective compliance assembly robotarm (SCARA) type. The robot 27 is located in the interface space 29 andis configured to include a robot arm 41, a horizontal drive means 42 a,a vertical drive means 42 b, a base 43, and a controller 44.

The robot arm 41 has a link structure including a plurality of linkmembers 41 a to 41 c which are successively connected in a directionfrom a proximal end to a distal end. A robot hand 40 is provided at thedistal end of the robot arm 41. The robot hand 40 has a holdingstructure which can hold the wafer 24. The holding of the wafer 24 isintended herein to express a state wherein the wafer 24 can be carriedby using the hand 40. Accordingly, the wafer 24 may be mounted onto,sucked or held by, the hand 40.

The horizontal drive means 42 a is adapted to drive the respective linkmembers 41 a to 41 c of the robot arm 41 to be angularly displaced aboutjoint axes A0 to A2, respectively. The robot arm 41 can drive the robothand 40 by using the horizontal drive means, such that the robot hand 40can be displaced in any position on a horizontal plane in a movableregion, due to the relative angular displacement of each link member 41a to 41 c. The horizontal drive means 42 a includes a motor adapted toprovide angular displacement in accordance with a signal to be givenfrom the controller 44, and a power transmission mechanism adapted totransmit power of the motor to each link member. The motor and the powertransmission mechanism are provided for each link member 41 a to 41 c.

The vertical drive means 42 b is adapted to drive the robot arm 41 to bedisplaced in the upward and downward directions Z. The vertical drivemeans 42 b includes a fixed portion and a movable portion, wherein themovable portion can be angularly displaced in the upward and downwarddirections relative to the fixed portion. The vertical drive means 42 bfurther includes a motor adapted to provide angular displacement inaccordance with a signal to be provided from the controller 44, and apower transmission mechanism which converts power of the motor intopower for direct advance of the movable portion relative to the fixedportion and transmit the power to the movable portion. The fixed portionof the vertical drive means 42 b is supported by the base 43. The base43 is adapted to support the vertical drive means 42 b and is fixed tothe interface space forming portion 28.

The controller 44 is adapted to control the horizontal drive means 42 aand the vertical drive means 42 b in accordance with a transferinstruction to be inputted from a predetermined operational program orfrom a user and move the robot hand 40 to a preset position. Thecontroller 44 includes a memory circuit for storing a predeterminedprogram, an operational circuit for calculating the operational programstored in the memory circuit, and an output means adapted to providesignals expressing results of the calculation given from the operationalcircuit to the horizontal drive means 42 a and the vertical drive means42 b. For example, the memory circuit can be achieved by a random accessmemory (RAM) and/or a read only memory (ROM), and the operationalcircuit can be realized by a central processing unit (CPU).

Due to fixation of a proximal end of the robot arm 41 to the movableportion of the vertical drive means 42 b, the controller 44 can driveand displace the robot hand 40 of the robot arm 41 to any position inthe forward and backward directions X, left and right directions Y andupward and downward directions Z, in a movable range. In addition, dueto the control of the horizontal drive means 42 a and the vertical drivemeans 42 b by virtue of the controller 44, the wafer 24 held by therobot hand 40 can be transferred. Thus, the wafer 24 can be transferred,along a predetermined route, between each FOUP 25 and the waferprocessing apparatus 22.

The robot hand 40 passes through the front opening 120 and is advancedinto the FOUP internal space 34 while the corresponding opener 26 a to26 d opens the FOUP-side door 61 so as to hold a wafer 24 contained inthe FOUP 25. Thereafter, the robot hand 40 is moved through theinterface space 29 while holding the wafer 24, passes through the rearopening 121, and is advanced into the processing space 33 of thesemiconductor processing apparatus 22 so as to place the held wafer 24onto a preset wafer holding position 107. Alternatively, the robot hand40 passes through the rear opening 121, and is advanced into theprocessing space 30 so as to hold the wafer 24 held in the wafer holdingposition 107. Subsequently, the robot hand 40 is moved through theinterface space 29 while holding the wafer 24, passes through the frontopening 120, and is advanced into the FOUP internal space 34 so as totransfer the held wafer 24 to a position for containing it in the FOUP25.

In this embodiment, since the four FOUP openers 26 a to 26 d areprovided, the robot hand 40 is set to be able to take out and put ineach wafer 24 relative to each FOUP 25 supported by each FOUP supportingportion 31 of each opener 26. The robot hand 40 can also carry the wafer24 taken out from the FOUP 25 to a holding position set in the aligner56 as well as can carry the wafer 24 taken out from the holding positionof the aligner 56 into the wafer processing apparatus 22.

The aligner 56 is located in the interface space 29 and positioned moreright than the fourth FOUP opener 26 d which is positioned on the mostright side (in the drawing) of the plurality of FOUP openers 26 a to 26d. The aligner 56 has a holding portion for holding each wafer 24, andis configured to rotate the wafer 24 held by the holding portion so asto align a notch or ori-flat (orientation flat) formed in the wafer 24with a predetermined direction. Accordingly, when the so-aligned wafer24 is held by the robot hand 40, the wafer 24 can be located in theprocessing apparatus 22 with its orientation adjusted. In this way, theprocessing apparatus 22 can provide a predetermined process with theorientation of each wafer 24 being properly controlled.

A central position of each wafer 24 held by the aligner 56 is set atapproximately the center of the interface space 29 in the forward andbackward directions X. The aligner 56 is located in a position that doesnot interfere with the travel of the robot hand 40 to each FOUP opener26. As such, in this embodiment, the aligner 56 is positioned more rightthan the fourth FOUP opener 26 d which is positioned on the most rightside.

As described above, the wafer transfer robot 27 is located in theinterface space 29, and serves to mainly move the robot hand 40 in theinterface space 29. The wafer transfer robot 27 is configured to makethe robot hand 40 pass through the front opening 120 so as to enableeach wafer 24 to be taken out from the FOUP internal space 34 as well asto enable the wafer 24 to be placed into the FOUP internal space 34. Thewafer transfer robot 27 is also configured to have the robot hand passthrough the rear opening 121 so as to enable each wafer 24 to be takenout from the wafer holding position 107 of the processing space 30 aswell as to enable the wafer 24 to be placed in the wafer holdingposition 107 of the processing space 30. Furthermore, the wafer transferrobot 27 is configured such that it can pass through the four frontopening 120 respectively provided in the four FOUP openers 26 a to 26 d.

Accordingly, the wafer transfer robot 27 is configured such that it cancarry the robot hand 40 in the forward and backward directions X over adistance greater than the length B in the forward and backwarddirections of the interface space 29. The wafer transfer robot 27 isconfigured to enable the robot hand 40 to be moved in the left and rightdirections Y such that it can access the FOUP 25 supported by each FOUPopener 26 a to 26 d. Moreover, in this embodiment, the wafer transferrobot 27 is configured to enable the robot hand 40 to be moved in theleft and right directions Y such that it can access the aligner 56.

The base 43 is fixed to the interface space forming portion 28, at whichthe predetermined pivot axis A0 is set. The pivot axis A0, in thisembodiment, extends in the vertical direction, and is positioned nearthe rear wall 111 in the interface space 29. The pivot axis A0 isdefined in a central position between the most left FOUP opener 26 a andthe most right FOUP opener 26 d in the left and right directions Y.

The robot arm 41 is configured to have a link structure in which theplurality of link members 41 a to 41 c are connected with one another. Aproximal end the robot arm 41 is defined at one end of an arrangement inwhich the plurality of link member 41 a to 41 c are successivelyarranged, and a distal end thereof is defined at the other end of thearrangement. The proximal end of the robot arm 41 is fixed to themovable portion of the vertical drive means 42 b, and is connected withthe base 43 via the vertical drive means 42 b. At the distal end of therobot arm 41, the robot hand 40 is provided. The robot arm 41 isconfigured such that the proximal end can be angularly displaced aboutthe pivot axis A0.

Specifically, the robot arm 41 includes the first to third link members41 a, 41 b, 41 c. Each of the link members 41 a to 41 c is formed intoan elongated shape extending in its longitudinal direction. The firstlink member 41 a is connected, at its one end 45 a in its longitudinaldirection, with the movable portion of the vertical drive means 42 b.The first link member 41 a is configured such that it can be angularlydisplaced about the pivot axis A0 relative to the movable portion of thevertical drive means 42 b. At the other end 46 a in the longitudinaldirection of the first link member 41 a, the first joint axis A1 is set,which is parallel with the pivot axis A0. Accordingly, the first jointaxis A1 is moved along with movement of the first link member 41 a. Thelongitudinal direction of the first link member 41 a is defined by aline connecting the pivot axis A0 with the first joint axis A1.

The second link member 41 b is connected, at its one end 45 b in itslongitudinal direction, with the other end 46 a in the longitudinaldirection of the first link member 41. The second link member 41 b isconfigured such that it can be angularly displaced about the first jointaxis A1 relative to the first link member 41 a. At the other end 46 b inthe longitudinal direction of the second link member 41 b, the secondjoint axis A2 is set, which is parallel with the pivot axis A0.Accordingly, the second joint axis A2 is moved along with movement ofthe second link member 41 b. The longitudinal direction of the secondlink member 41 b is defined by a line connecting the first joint axis A1with the second joint axis A2.

The third link member 41 c is connected, at its one end 45 c in itslongitudinal direction, with the other end 46 b in the longitudinaldirection of the second link member 41 b. The third link member 41 c isconfigured such that it can be angularly displaced about the secondjoint axis A2 relative to the second link member 41 b. At the other end46 c in the longitudinal direction of the third link member 41 c, therobot hand 40 is provided. Accordingly, the robot hand 40 is moved alongwith movement of the third link member 41 c. The longitudinal directionof the third link member 41 c is defined by a line connecting the secondjoint axis A2 with the central position A3 of the wafer 24 which is heldby the robot hand 40.

In this manner, the robot arm has the link structure comprising thethree link members 41 a to 41 c. The horizontal drive means 42 aincludes first to third motors. The first motor is adapted to rotate anddrive the first link member 41 a about the pivot axis A0. The secondmotor is adapted to rotate and drive the second link member 41 b aboutthe first joint axis A1. The third driving source is a motor whichserves to rotate and drive the third link member 41 c about the secondjoint axis A2. As such, the horizontal drive means 42 a can angularlydisplace the first to third link members 41 a to 41 c, individually,about the corresponding angular displacement axes A0 to A2,respectively.

As shown in FIG. 2, the second link member 41 b is located above thefirst link member 41 a. Thus, the second link member 41 b can be movedin a position which is overlapped with the first link member 41 a in theupward and downward directions Z, thereby to prevent interference of thefirst link member 41 a with the second link member 41 b. Similarly, thethird link member 41 c is located above the second link member 41 b.Accordingly, the third link member 41 c can be moved in a position whichis overlapped with the second link member 41 b, as such preventing eachinterference of the first link member 41 a to the third link member 41c.

FIG. 3 is a plan view showing the wafer transfer apparatus 23, which issimplified, for explaining a length of each link member 41 a to 41 c.Due to the angular displacement of each link member 41 a to 41 c abouteach corresponding angular displacement axis A0 to A2, the robot arm 41can be transformed into its minimum state. A minimum transformed statemeans a transformed state wherein a distance, defined from the pivotaxis A0 to an arm portion, which extends in the horizontal direction andis the farthest in the radial direction from the pivot axis A0, is theminimum. More specifically, the minimum transformed state means atransformed state wherein a distance, from the pivot axis A0 to an armportion or a portion of the wafer 24, which is the farthest in theradial direction from the pivot axis A0, with the wafer 24 being held bythe robot arm 41, is the minimum.

Hereinafter, in the minimum transformed state, the distance, from thepivot axis A0 to the arm portion or wafer portion, which is farthest inthe radial direction relative to the pivot axis A0, will be referred toas “the minimum rotation radius R of the robot.” The length between thefront wall 110 and the rear wall 111 constituting the interface space 29in the forward and backward directions X will be referred to as “thelength B of the interface space in the forward and backward directions.”

In this embodiment, the minimum rotation radius R of the robot is longerthan a half (½) of the length B of the interface space in the forwardand backward directions. In addition, the minimum rotation radius R isset to be equal to or less than a subtracted value (B−L0) obtained bysubtracting a distance L0 in the forward and backward directions fromthe rear wall 111 to the pivot axis A0, from the length B of theinterface space in the forward and backward directions (i.e.,B/2<R≦B−L0). Accordingly, even when the robot arm 41 is transformed intoits minimum transformed state, an amount of angular displacement of therobot arm 41 is restricted such that it can be angularly displaced aboutthe pivot axis A0 within an allowable angular displacement range thatcan prevent interference of the robot arm 41 with the rear wall 111. Inthis embodiment, the allowable angular displacement range is set to besmaller than 360 degrees, for example, about 180 degrees, about thepivot axis A0. Thus, interference of the robot 27, which is maintainedin the minimum transformed state, with the front wall 110 as well aswith the rear wall 111 can be prevented, as long as it is operatedwithin the allowable angular displacement range.

The distance L0 in the forward and backward directions from the rearwall 111 to the pivot axis A0 is set at, at least, a value smaller than½ of the length B in the forward and backward directions of theinterface space (i.e., L0<B/2). In this embodiment, the distance L0 inthe forward and backward directions from the rear wall 111 to the pivotaxis A0 is set to be less than ⅕ of the length B in the forward andbackward directions of the interface space (i.e., L0<B/5). Furthermore,the distance L0 in the forward and backward directions from the rearwall 111 to the pivot axis A0 is set to be greater by a predeterminedgap length Q than a radius T2 of an outer circumference of the firstlink member 41 a about the pivot axis A0, over the whole area whereinthe outer circumference of the first link member 41 a is on the oppositeside of the first joint axis A1 with respect to the pivot axis A0 (i.e.,L0=T2+Q). The predetermined gap length Q is sufficient for preventingthe interference that would be otherwise caused by the robot, and inthis embodiment, it is set at 30 mm.

More specifically, in this embodiment, the minimum rotation radius R ofthe robot is set to exceed ½ of an allowable length (B−L0−E) to beobtained by subtracting the distance L0 in the forward and backwarddirections from the rear wall of the interface space forming portion tothe pivot axis and a length E of a robot invasion restricted region,which is set for each FOUP opener 26 and is measured from the front wall110, in the forward and backward directions X, on the rear wall side,from the length B in the forward and backward directions of theinterface space, as well as set to be equal to or less than theallowable length (B−L0−E) (i.e., ((B−L0−E)/2<R≦B−L0−E). Thus,interference of the robot 27, which is maintained in its minimumtransformed state, with each FOUP opener 26 can be prevented.

A distance from the pivot axis A0 to an end of the first link member 41a, which is the farthest in the axial direction toward the first jointaxis A1 relative to the pivot axis A0, is referred to as a first linkdistance L1. The first link distance L1 is set to exceed ½ of theallowable length (B−L0−E) described above and to be equal to or lessthan the allowable length (B−L0−E) (i.e., ((B−L0−E)/2<L1≦B−L0−E). Thefirst link member 41 a is formed such that a radius T1 of the outercircumference of the first link member 41 a about the first joint axisA1 is equal to or less than a value to be obtained by subtracting thedistance L11 (first axis-to-axis distance) between the pivot axis A0 andthe first joint axis A1, from the allowable length (B−L0−E), over thewhole area wherein the outer circumference of the first link member 41 ais on the opposite side of the pivot axis A0 with respect to the firstjoint axis A1 (i.e., T1≦B−L0−E−L11).

The first link member 41 a is formed such that the radius T2 of theouter circumference of the first link member 41 a about the pivot axisA0 is less than the distance L0 in the forward and backward directionsfrom the rear wall 111 to the pivot axis A0, over the whole area whereinthe outer circumference of the first link member 41 a is on the oppositeside of the first joint axis A1 with respect to the pivot axis A0 (i.e.,T2<L0). Consequently, even in the case where the first link member 41 ais angularly displaced by 90 degrees, from a state wherein thelongitudinal direction of the first link member 41 a is coincident withthe forward and backward directions X, in one of the circumferentialdirections about the pivot axis A0, or alternatively, even in the casewhere it is angularly displaced by 90 degrees from the above state inthe other circumferential direction about the pivot axis A0,interference of the first link member 41 a with the rear wall 111 can beprevented.

In this embodiment, the first axis-to-axis distance L11 between thepivot axis A0 and the first joint axis A1 and the second axis-to-axisdistance L12 between the first joint axis A1 and the second joint axisA2 are set to be the same. As used herein, the term “the same” isintended to imply a state that is substantially the same, as suchreferring to both the same and substantially the same states. In thisembodiment, a distance from the second joint axis A2 to an end of thesecond link member 41 b, which is the farthest in the direction towardthe first joint axis A1 relative to the second joint axis A2, isreferred to as a second link distance L2. The second link distance L2 isset to exceed ½ of the allowable length (B−L0−E) and to be equal to orless than the allowable length (B−L0−E) (i.e., (B−L0−E)/2<L2≦B−L0−E).

The second link member 41 b is formed such that a radius T3 of the outercircumference of the second link member 41 b about the first joint axisA1 is equal to or less than a value (B−L0−E−L11) to be obtained bysubtracting the first axis-to-axis distance L11 from the allowablelength (B−L0−E), over the whole area wherein the outer circumference ofthe second link member 41 b is on the opposite side of the second jointaxis A2 with respect to the first joint axis A1 (i.e., T3≦B−L0−E−L11).The second link member 41 b is formed such that a radius T4 of the outercircumference of the second link member 41 b about the second joint axisA2 is smaller than the distance L0 in the forward and backwarddirections from the rear wall 111 to the pivot axis A0, over the wholearea wherein the outer circumference of the second link member 41 b ison the opposite side of the first joint axis A1 with respect to thesecond joint axis A2 (i.e., T4<L0).

In this embodiment, in a state wherein the robot hand 40 holds the wafer24, a distance from the second joint axis A2 to an end of the third linkmember 41 c or a wafer portion, which is the farthest from the secondjoint axis A2 in the radial direction with respect to the second jointaxis A2, is referred to as a third link distance L3. The third linkdistance L3 is set to exceed ½ of the allowable length (B−L0−E) and tobe equal to or less than the allowable length (B−L0−E) (i.e.,((B−L0−E)/2<L1≦B−L0−E). The third link member 41 c is formed such that aradius T5 of the outer circumference of the third link member 41 c aboutthe second joint axis A2 is smaller than the distance L0 in the forwardand backward directions from the rear wall 111 to the pivot axis A0,over the whole area wherein the outer circumference of the third linkmember 41 c is on the opposite side of the wafer holding centralposition A3 with respect to the second joint axis A2 (i.e., T5<L0).

In this embodiment, the first link distance L1 and the second linkdistance L2 are set to be equal to the allowable length (B−L0−E). Thefirst axis-to-axis distance L11 and the second axis-to-axis distance L12are set to be the same distance that enables the wafer 24 supported byeach FOUP opener 26 a to 26 d to be taken out therefrom. In thisembodiment, the third link distance L3 is also set to be the same as theallowable length (B−L0−E). As shown in FIG. 3, the robot hand 40 is setsuch that it can hold the wafer 24 in a state wherein the first linkmember 41 a and the second link member 41 b are extended in a straightline.

In the case where the third link member 41 is located in a position tohold the wafer 24 contained in the first FOUP 25 a supported by thefirst FOUP opener 26 a, a distance in the forward and backwarddirections X from the second joint axis A2 to the pivot axis A0 isdesignated by S1. A distance in the left and right directions from thesecond joint axis A2 to the pivot axis A0 is designated by S2. Inaddition, a distance obtained by summing up the first axis-to-axisdistance L11 and the second axis-to-axis distance L12 is expressed by(L11+L12).

In this embodiment, each axis-to-axis distance L11, L12 is set tosatisfy the following relation ship: (L11+L12) =(S1 ²+S2 ²)^(0.5).Because each axis-to-axis distance L11, L12 is set to be equal, eachaxis-to-axis distance L11, L12 is defined as ((S1 ²+S2 ²)/4)^(0.5).Thus, as shown in FIG. 3, the robot hand 40 can reach the wafer 24contained in the first FOUP 25 a while the longitudinal direction of thefirst link member 41 a and the longitudinal direction of the second linkmember 41 b are arranged to constitute together a straight line. Sincethe pivot axis A0 is located in a central position relative to the FOUPopeners 26 a to 26 d, the robot hand 40 can also reach the wafer 24contained in the fourth FOUP 25 d while the longitudinal direction ofthe first link member 41 a and the longitudinal direction of the secondlink member 41 b are arranged to constitute together a straight line. Inthis way, since the first link member 41 a and the second link member 41b can take a form to constitute together a straight line, each of thefirst axis-to-axis distance L11 and second axis-to-axis distance L12 canbe significantly reduced.

In addition, the robot hand 40 may be configured to reach the wafer 24contained in the first FOUP 25 a or fourth FOUP 25 d while the thirdlink member 41 c is inclined to the forward and backward directions X.As such, each of the first axis-to-axis distance L11 and secondaxis-to-axis distance L12 can be further reduced.

In this embodiment, each space in the left and right directions Ybetween the wafer central positions A3 of the wafers 24 contained in thefirst FOUP 25 a to fourth FOUP 25 d is designated by W. In addition, inthe state wherein the robot hand 40 reaches the wafer 24 contained inthe first FOUP 25 a, an angle at which the third link member 41 isinclined relative to the forward and backward directions X is expressedby θ. In this state, a distance from the wafer central position A3 tothe second joint axis A2 is designated by H. Also in this state, a value(S1−L11) to be obtained by subtracting the first axis-to-axis distanceL11 from the distance S1 in the forward and backward directions from thesecond joint axis A2 to the pivot axis A0 is expressed by C. Using theseexpressions, the first axis-to-axis distance L11 can be expressed asfollows.(2·L11)²≧(L11+C)²+(1.5·W−H·Sin θ)²   (1)

For example, in the case where C=0, θ=0, and W=505 mm, each axis-to-axisdistance L11, L12 is equal to or greater than 437.3 mm. Now, assume thatthe length E of the robot invasion restricted region in the forward andbackward directions X, which is set for each FOUP opener 26 and ismeasured from the front wall 110 on the rear wall side, is 100 mm. Inaddition, assume that the distance L0 in the forward and backwarddirections from the rear wall 111 to the pivot axis A0 is 65 mm, andthat a distance L10 (R−L11) to be obtained by subtracting the firstaxis-to-axis distance L11 from the minimum rotation radius R of therobot is 50 mm. The resultant length B in the forward and backwarddirections of the interface space is equal to or greater than 652.3 mm(i.e., B≧L11+E+L0+L10). In other words, if the length B in the forwardand backward directions of the interface space is 652.3 mm, the wafer 24contained in each of the first and fourth FOUPs 25 a, 25 d supported byeach corresponding FOUP opener 26 a, 26 d can be taken out, by settingeach axis-to-axis distance L11, L12 at 437.3 mm. Of course, the wafer 24contained in each of the second and third FOUPs 25 b, 25 c, which arelocated nearer to the pivot axis A0 than the first and fourth FOUPs 25a, 25 d, can also be taken out.

In this embodiment, the length B in the forward and backward directionsof the interface space is 694 mm. The minimum rotation radius R of therobot is set at 485 mm, and the first axis-to-axis distance L11 and thesecond axis-to-axis distance L12 are each set at 425 mm. In the statewherein the wafer 24 is held by the robot hand 40, the distance H fromthe second joint axis A2 to the wafer central position A3 is set at 320mm. In addition, the third link distance L3 is set at 470 mm.

For example, if θ=5°, H=330 mm, and the other conditions are the same asdescribed above, each axis-to-axis L11, L12 to be obtained is equal toor greater than 420.4 mm, and the length B in the forward and backwarddirections of the interface space is to be equal to or greater than635.4 mm. Alternatively, if C=10 mm, θ=5°, H=330 mm, and the otherconditions are the same as described above, each axis-to-axis L11, L12to be obtained is equal to or greater than 417.5 mm and the length B inthe forward and backward directions of the interface space is to beequal to or greater than 632.5 mm.

By inclining the longitudinal direction of the third link member 41 crelative to the forward and backward directions X in the state whereinthe robot hand 40 reaches the wafer 24, the wafer contained in each FOUP25 a to 25 d can be taken out without unduely extending the first linkmember 41 a and the second link member 41 b.

In the embodiment described above, due to the pivot axis A0 arrangednear the rear wall 111 and due to the minimum rotation radius R of therobot arm 41, which is set to exceed ½ of the subtracted value (B−L0)and to be equal to or less than the subtracted value (B−L0), a gap canbe securely provided between the robot arm 41, which is in the minimumtransformed state, and the front wall 101, as such preventinginterference of the robot arm 41 with the front wall 101. Accordingly,the robot hand 40 can be located, on both sides in the left and rightdirections Y, with respect to a reference line P0 extending in theforward and backward directions X and including the pivot axis A0.

In addition, since the robot arm 41 can be operated in an operationalrange excluding such a range that would potentially interfere with therear wall 111, the interference of the robot with the rear wall 111 canalso be prevented. Accordingly, while the length B in the forward andbackward directions of the read space is relatively small, each wafer 24contained in a plurality of, for example, four, FOUPs, i.e., the firstto fourth FOUP 25 a to 25 d, supported by the four FOUP openers 26 a to26 d, can be taken out, by using the robot arm 41 having the linkstructure comprising the three link members 41 a to 41 c.

In this embodiment, by setting the minimum rotation radius R of therobot to be equal to or less than the allowable length (B−L0−E), eventhough the robot arm 41 taking its minimum transferred state approachesnearest relative to the front wall 101, entering of a part of the robotarm 41 into the robot invasion restricted region E of each FOUP opener26 a to 26 d can be prevented. Thus, interference between the robot arm41 with each FOUP opener 26 a to 26 d can be prevented, regardless of amovable range or state of each FOUP opener 26 a to 26 d.

The first to third link distances L1 to L3 are set to exceed ½ of theallowable length (B−L0−E) and to be equal to or less than the allowablelength (B−L0−E). As a result, the length of each link member 41 a to 41c can be significantly enlarged. Therefore, even in the case where thelength B in the forward and backward directions of the interface spaceis relatively small, the robot hand 40 can be extended to a positionwhich is significantly spaced away from the pivot axis A0 on both sidesin the left and right directions Y. Thus, even in the case where thenumber of the FOUP openers 26 is quite increased, the wafer 24 can becarried with the simple link structure as described above. In thisembodiment, the first to third link distances L1 to L3 are each set tobe the same as the allowable length (B−L0−E). Consequently, interferenceof the robot arm 41 with the front wall 110 as well as with each FOUPopener 26 can be prevented, and the length of each link member 41 a to41 c can be increased to the maximum.

With the increase of the link length of each link member 41 a to 41 c ofthe robot arm 41, the movable range of the robot arm 41 can be enlargedwith respect to the left and right directions Y. Accordingly, ascompared with the second related art, the running means which is adaptedto drive the robot 27 to run in the left and right directions Y can beexcluded, thus eliminating the direct acting mechanism. As such,occurrence of dust to be associated with the direct acting mechanism canbe prevented, and hence degradation of cleanliness in the interfacespace 29 due to such dust can be avoided. Additionally, the eliminationof the running means can ensure downsizing and weight reduction of therobot 27.

In addition, with the increase of the link length of each link member 41a to 41 c of the robot arm 41, the robot hand can reach a predeterminedposition in a wider range. Furthermore, increase of the number of thelink members can be controlled, as such simplifying the structure of therobot 27. In addition, redundancy of the robot 27 can be reduced, thussimplifying teaching works concerning control and transformed states forthe robot arm 41. Therefore, possibility of collision of the robot arm41 with the interface space forming portion 28 as well as with each FOUPopener 26 can be reduced.

As described above, in this embodiment, scattering of dust can besuppressed due to exclusion of the running means, as well as, theinterference of the robot with the interior of the wafer transferapparatus 23 can be prevented, as such providing the wafer transferapparatus 23 comprising the wafer transfer robot 23 which has asignificantly simplified structure and can be readily controlled. Inaddition, the number of the FOUP openers 26 can be increased withoutenlarging the length B in the forward and backward directions of theinterface space 29. With the increase of the number of the FOUP openers26, carrying, attaching and detaching operations of each FOUP 25relative to the wafer transfer apparatus 23 and a transfer operation ofeach wafer contained in each FOUP 25 held by the wafer transferapparatus 23 can be performed in parallel, thereby to enhance theworking efficiency.

Because the length B in the forward and backward directions of theinterface space 29 can be reduced, a space for installment of the wafertransfer apparatus 23 can be downsized. Therefore, restrictionsregarding the installment space can be lightened, thus in turnfacilitating installment of the wafer processing equipment 20. Withreduction of the length B in the forward and backward directions of theinterface space 29, as compared with a case in which the length B in theforward and backward directions of the interface space 29 is longer, thecleanliness in the interface space 29 can be enhanced as well as theyield can be improved, by using the interface space controller 100provided with the same function.

In this embodiment, the length B in the forward and backward directionsof the interface space can be reduced by designing the robot hand 40such that the longitudinal direction of the third link member 41 c canbe inclined relative to the forward and backward directions X in thestate wherein the robot hand 40 reaches the corresponding wafer 24.Thus, even in the case where the first and second axis-to-axis distancesL11, L12 are set to be shorter in order to prevent interference of therobot hand 40 with the interface space forming portion 28 and/or eachFOUP opener 26, holding of the wafer 24, which is held by the FOUP 25supported by each corresponding FOUP opener, can be performed with ease.

Since the length of each link member 41 a to 41 c can be increased, ascompared with a case in which the length of each link member 41 a to 41c is shorter, a transfer speed of the robot hand can be enhanced, evenwith the angular speed upon angular displacement about the correspondingpivot axes A0 to A2 being the same. By driving both of the first linkmember 41 a and second link member 41 b, force of inertia can bereduced. Due to this function, the transfer speed of the robot hand 40can also be enhanced. With such enhancement of the transfer speed of therobot hand 40, the time required for carrying each wafer 24 can bereduced, thereby to enhance the working efficiency.

FIG. 4 is a diagram showing a carrying operation, which is simplified,for carrying the wafer 24 contained in the first FOUP 25 a to thealigner 56. The carrying operation proceeds in the order of from FIG.4(1) to FIG. 4(7). The carrying operation shown in FIG. 4 is stored inthe controller 44, with respect to the transfer route and passingthrough points of the robot hand 40. The controller 44 serves to controlthe horizontal drive means 42 a and the vertical drive means 42 b byexecuting a predetermined operational program, such that the robot hand40 passes through a plurality of points along the transfer route.Consequently, the wafer transfer robot 27 can carry each wafer 24contained in the first FOUP 25 a to the aligner 56.

First, the robot arm 41 is moved vertically up to the wafer 24 to beheld, and then transformed such that the first link member 41 a and thesecond link member 41 b are extended in a straight line, as shown inFIG. 4(1), so as to hold the wafer 24 contained in the first FOUP 25 aby using the hand 40. Next, as shown in FIG. 4(2), the first link member41 a and the second link member 41 b are angularly displaced about thecorresponding angular displacement axes A0, A1, respectively, so as tomove the third link member 41 c in the backward direction X2 into theinterface space 29 together with the wafer 24.

Subsequently, the first link member 41 a and the second link member 41 bare further angularly displaced about the corresponding angulardisplacement axes A0, A1, respectively, so as to move the third linkmember 41 c in parallel to the left and right directions Y, toward thealigner 56 located in a position far away from the first FOUP opener 26a in the left and right directions Y. At this time, because the firstaxis-to-axis distance L11 and the second axis-to-axis distance L12 areset to be equal, as shown in FIGS. 4(3) and 4(4), the second link member41 b is angularly displaced about the first joint axis A1, in an amountof angular displacement per unit time, which is twice the amount ofangular displacement per unit time, relative to the angular displacementof the first link member 41 a about the pivot axis A0. In this manner,the third link member 41 c can be moved in parallel to the left andright directions Y, without angularly displacing the third link member41 c about the second joint axis A2, and without altering the attitudeof the third link member 41 c.

In the case of locating the third link member 41 c on the aligner 56with its attitude altered, as shown in FIGS. 4(5) to 4(7), the wafer 24can be located in a holding position set in the aligner 56, by angularlydisplacing the first to third link members 41 a to 41 c about thecorresponding angular displacement axes A0 to A2, respectively. In orderto enable the aligner 56 to hold the wafer 24, after the robot arm 41has held the wafer 24 and by the time it carries the wafer 24 to thealigner 56 so as to make the aligner 56 hold the wafer 24, the positionin the upward and downward directions of the robot arm 41 is adjusted bythe vertical drive means 42 b. In this manner, the wafer transfer robot27 can carry the wafer 24, which has been contained in the first FOUP 25a, to the aligner 56.

FIG. 5 is a diagram showing a carrying operation, which is simplified,for carrying the wafer 24 supported by the aligner 56 into theprocessing space 30. The carrying operation proceeds in the order offrom FIG. 5(1) to FIG. 5(7). Similar to the case shown in FIG. 4, thewafer transfer robot 27 can carry the wafer 24 held by the aligner 56into the processing space 30, by controlling the horizontal drive means42 a and the vertical drive means 42 b in accordance with thepredetermined program.

In the case of carrying the wafer 24 into the processing space 30, thehand 40 should be directed in the backward direction X2. Accordingly, asshown in FIG. 5(1), from a state wherein the second joint axis A2 hasbeen moved in the backward direction X2 in the interface space 29 whilethe third link member 41 c holding the wafer 24, the third link member41 c is angularly displaced about the second joint axis A2 as well asthe second joint axis A2 is moved in the forward direction X1 in theinterface space 29. In the example shown in FIG. 5, after the third linkmember 41 c has been angularly displaced by about 120 degrees, thesecond joint axis A2 is moved in the forward direction X1 in theinterface space 29, and the third link member 41 c is then furtherangularly displaced.

Thus, the orientation of the third link member 41 a can be altered by180 degrees in the interface space 29 without any interference of thethird link member 41 a with the front wall 110, rear wall 111 and eachFOUP opener 26. Accordingly, as shown in FIGS. 5(2) to 5(6), after theorientation of the third link member 41 c has been altered, as shown inFIG. 5(7), the wafer 24 can be carried into the processing space 30. Inorder to enable the robot arm 41 to be moved into the processing space30 after it has held the wafer 24 and by the time it is moved toward theprocessing space 30, the position in the upward and downward directionsof the robot arm 41 is controlled by the vertical drive means 42 b. Inthis way, the wafer transfer robot 27 can carry the wafer 24, which hasbeen held by the aligner 56, into the processing space 30.

FIG. 6 is a diagram showing a carrying operation, which is simplified,for carrying the wafer 24 located in the processing space 30 to thefirst FOUP 25 a. Similar to the case shown in FIG. 4, the controllercontrols the horizontal drive means 42 a and the vertical drive means 42b in accordance with the predetermined program so that the wafertransfer robot 27 can carry the wafer 24 contained in the processingspace 30 to the first FOUP 25 a.

First, the robot arm 41 is moved upward and downward to a position ofthe wafer 24 to be held as well as the robot arm 41 is transformed, asshown in FIG. 6(1), so as to hold the wafer 24 in the processing space30. Subsequently, as shown in FIG. 6(2), the first link member 41 a andthe second link member 41 b are angularly displaced about thecorresponding angular displacement axes A0, A1, respectively, and thethird link member 41 c is moved in the forward direction X1, so as tomove the third link member 41 c and the wafer 24 into the interior ofthe interface space 29. Thereafter, as shown in FIGS. 6(3) and 6(4),while the position of the second joint axis A2 is adjusted in order toprevent interference due to the third link member 41 c, the third linkmember 41 c is rotated about the second joint axis A2 to alter itsattitude, thus changing the orientation of the third link member 41 c.Next, as shown in FIGS. 6(4) and 6(5), the first link member 41 a andthe second link member 41 b are angularly displaced about thecorresponding angular displacement axes A0, A1, respectively, so as tomove the third link member 41 c in parallel to the left and rightdirections Y. Thereafter, as shown in FIG. 6(6), a portion on the robothand side of the third link member 41 c is positioned to face the frontopening as well as maintained in an attitude which is substantiallyparallel to the forward and backward directions X. In this state, theposition of the hand 40 in the upward and backward directions isadjusted to enable the wafer to be contained in the FOUP. As such, thewafer is contained in the space in the FOUP 25 as shown in FIG. 6(7).

FIG. 7 is a diagram showing a state in which the wafer 24 is located inits receiving and transferring positions of the embodiment according tothe present invention. FIGS. 7(1) to 7(4) depict states wherein thewafers 24 contained in the first to fourth FOUPs 25 a to 25 d are held,respectively. FIG. 7(5) shows a state in which the wafer 24 is locatedat the aligner 56. FIGS. 7(6) and 7(7) show states wherein the wafer 24is located in positions set in the processing space 30, respectively. Asillustrated, this embodiment can be configured to include the robot armhaving the three-link type structure so as to enable receiving andtransferring of the wafers 24 in the FOUPs 25 supported by the four FOUPopeners 26 a to 26 d, respectively.

While, this embodiment comprises the single third link member 41 cprovided in the robot hand 40, it is not limited to this aspect. Namely,in the present invention, it is also contemplated that a plurality of,for example, two, third link members 41 c may be provided.

For example, in the case where a plurality of third link members 41 care provided, these third link members 41 c are provided to be arrangedin the upward and downward directions Z, respectively. Each third linkmember 41 c is connected, at its one end 45 c in the longitudinaldirection, with the other end 46 b in the longitudinal direction of thesecond link member 41 b. Each third link member 41 c is configured suchthat it can be angularly displaced, individually, about the second jointaxis A2 relative to the second link member 41 b. In addition, each thirdlink member 41 c is provided with the robot hand 40 formed at the otherend thereof in the longitudinal direction. Due to arrangement of eachthird link member 41 c in a region different in the upward and downwarddirections, even though they are angularly displaced, individually,about the second joint axis A2, mutual interference between the thirdlink members 41 c can be prevented. In addition, due to such provisionof the plurality of third link members 41 c, the number of sheets of thewafers that can be carried at a time can be increased, as such enhancingthe working efficiency. It should be appreciated that the number of thethird link members is not limited to one or two but three or more thirdlink members 41 c may be provided. It is preferred that each third linkmember 41 c is formed to have the same shape.

FIG. 8 is a plan view showing the wafer transfer apparatus 23 includingthree FOUP openers 26. FIG. 9 is a plan view showing the wafer transferapparatus 23 including two FOUP openers 26. In FIGS. 8 and 9, oneexample of additional working forms of a robot 27 is depicted by chaindouble-dashed lines. The wafer transfer robot 27 shown in FIGS. 8 and 9is configured similarly to the wafer transfer robot 27 used in the wafertransfer apparatus 23 including the four FOUP openers 26. Accordingly,the wafer transfer robot 27 can carry each wafer without causing anyinterference with the front wall 110 and the rear wall 111, also in thecase of including the two or three FOUP openers 26. As such, there is noneed for changing the configuration of the robot depending on the numberof the FOUP openers 26, thereby to enhance applicability for generalpurposes.

FIG. 10 is a plan view showing a wafer transfer apparatus 23A which is asecond embodiment of the present invention, and is somewhat simplified.The wafer transfer apparatus 23A of the second embodiment includesportions similar to those in the wafer transfer apparatus 23 of thefirst embodiment described above. Thus, such like parts are notdescribed here, and designated by like reference numerals. Specifically,the wafer transfer apparatus 23A of the second embodiment is differentfrom the first embodiment in the length of the wafer transfer robot 27,but is the same as the first embodiment in regard to the otherconfiguration.

The first embodiment is configured such that the robot hand 40 reachesthe wafer 24 contained in the first FOUP 25 a with the first link member41 a and the second link 41 b extended together in a straight line.However, the present invention is not limited to this aspect. Namely, inthe second embodiment, the robot hand 40 reaches the wafer 24 containedin the first FOUP 25 a with the longitudinal direction of the linkmember 41 a and the longitudinal direction of the second link member 41b defining a predetermined angle a.

In the second embodiment, angular positions of the first link member 41a and the second link member 41 b are respectively set such that therobot hand 40 reaches the wafer 24, with the longitudinal direction ofthe third link member 41 c being coincident with the forward andbackward directions X. Namely, in the second embodiment, the hand 40reaches the wafer 24, with the longitudinal direction of the third linkmember 41 c being coincident with the forward and backward directions X,and the third link member 41 c is then moved in parallel to the backwarddirection X2, so as to carry the wafer 24 into the interface space 29.Thus, even in the case where a gap between the wafer held by the hand 40and the front opening 101 a as well as the opening 60 a of the FOUP mainbody 60 is relatively small, collision of the wafer 24 with each opening101 a, 60 a can be prevented.

Also in the second embodiment, by locating the pivot axis A0 near therear wall 111 and by setting the minimum rotation radius R of the robotarm 41 to exceed ½ of the subtracted value (B−L0) described above and tobe equal to or less than the subtracted value (B−L0), the same effect asin the first embodiment can be obtained.

FIG. 11 is a plan view showing a wafer transfer apparatus 23B which is athird embodiment of the present invention, and is somewhat simplified.In FIG. 11, one example of additional working forms of a robot 27 isdepicted by chain double-dashed lines. The wafer transfer apparatus 23Bof the third embodiment includes portions similar to those in the wafertransfer apparatus 23 of the first embodiment described above. Thus suchlike parts are not described here, and designated by like referencenumerals. Specifically, the wafer transfer apparatus 23B of the thirdembodiment is different from the first embodiment in the length of thewafer transfer robot 27, but is the same as the first embodiment inregard to the other configuration.

In the first embodiment, the first axis-to-axis distance L11 and thesecond axis-to-axis distance L12 are of the same length. However, thisinvention is not limited to this aspect. In the third embodiment, thereis some difference in the length between the first axis-to-axis distanceL11 and the second axis-to-axis distance L12, and the first axis-to-axisdistance L11 is provided to be slightly longer than the secondaxis-to-axis distance L12. In this case, as shown in FIG. 11, whenangularly displacing the second link member 41 b about the first jointaxis A1, in an amount of angular displacement per unit time, which istwice the amount of angular displacement per unit time, relative to theangular displacement of the first link member 41 a about the pivot axisA0 while the angular displacement of the third link member 41 c aboutthe second joint axis A2 is stopped, the attitude of the third linkmember 41 c is changed slightly.

When the robot hand 40 is advanced from one end to the other end in theleft and right directions Y relative to the pivot axis A0, transfertracks 130, 131 of the central position A3 of the wafer 24 held by thehand 40 and the second joint axis A2 depict circular arcs both beingconvex in the forward direction X, respectively. In FIG. 11, in order tofacilitate understanding, the transfer tracks 130, 131 of the centralposition A3 and the second joint axis A2 are respectively depicted bydashed lines, while corresponding imaginary lines 132, 133 extending inparallel with the left and right directions Y are respectively expressedby chain lines.

In this case, when the difference in the length between the firstaxis-to-axis distance L11 and the second axis-to-axis distance L12 isquite small, the third link member 41 c can be moved in substantiallyparallel to the left and right directions Y. In such a manner, the firstaxis-to-axis distance L11 and the second axis-to-axis distance L12 maybe provided with slight alteration. For example, an acceptabledifference in the length between the first axis-to-axis distance L1 andthe second axis-to-axis distance L12 may be set within (B−L0−E−L1) mm.

Also in the third embodiment described above, by locating the pivot axisA0 near the rear wall 111 and by setting the minimum rotation radius Rof the robot arm 41 to exceed ½ of the subtracted value (B−L0) describedabove and to be equal to or less than the subtracted value (B−L0), thesame effect as in the first embodiment can be obtained. The length ofeach link member 41 a to 41 c of the robot arm 41 and each axis-to-axisdistance L11, L12 of the first to third embodiments are described by wayof example, and hence may be altered. For example, the first linkdistance L11, second link distance L12 and third link distance L13 maynot necessarily be the same.

FIG. 12 is a plan view showing a part of semiconductor processingequipment 20C which is a fourth embodiment of the present invention. Thesemiconductor processing equipment 20C of the fourth embodiment includesportions similar to those in the wafer transfer apparatus 23 of thefirst embodiment described above. Thus such like parts are not describedhere, and designated by like reference numerals. In the semiconductorprocessing equipment 20 c of the fourth embodiment, the wafer transferrobot 27 of the wafer transfer apparatus 23 also serves as a carrierprovided in the wafer processing apparatus 22. In regard to the otherconfiguration, the semiconductor processing equipment 20 c is the sameas the first embodiment. As such, descriptions on that point are omittedhere.

In the first embodiment, the carrier included in the wafer processingapparatus 22 receives the wafer 24 to be carried into the processingspace 30 from the interface space 29 by the wafer transfer apparatus 23,and then carries the received wafer 24 into the wafer processingposition. On the other hand, in the fourth embodiment, since the wafertransfer robot 27 of the wafer transfer apparatus 23 can extend itsoperational region as shown in FIG. 12, it can transfer the wafer notonly in the wafer transfer apparatus 23, but can also be advanced intothe processing space 30 of the wafer processing apparatus 22 so as todirectly transfer the wafer 24 to the wafer processing position.Accordingly, there is no need for a carrier in the wafer processingapparatus 22, thus reducing the number of elements in the waferprocessing equipment, thereby reducing the production cost.

In the fourth embodiment, it is preferred that the rear opening 121 isprovided in the vicinity of the pivot axis A0 with respect to the leftand right directions Y. It is also preferred that the rear opening 121is formed to have a space extending longer than a distance between afirst crossing point P1 that is one of two crossing points, at which animaginary circle defined to make a circuit around the pivot axis A0,with its radius being the minimum rotation radius R of the robot 27,crosses the rear-face-side wall 111 and a second point P2, at which aline passing through the pivot axis A0 and extending in the forward andbackward directions X crosses the rear-face-side wall 111, as such thespace is shaped to include both of the first crossing point P1 and thesecond crossing point P2. Consequently, in the case of angularlydisplacing the first link member 41 a about the pivot axis A0,interference of the first link member 41 a with the rear-face-side wall111 can be prevented. Thus, the first joint axis A1 set in the firstlink member 41 a can be located also in the processing space 30.Accordingly, the wafer 24 can be transferred to a position away from therear wall 111 in the backward direction X2 in the processing space 30.

Each of the embodiments 1 to 4 described above is illustrated by way ofexample, and of course may be modified within the scope of thisinvention. For example, while in these embodiments, the wafer transferapparatus 23 used in the wafer processing equipment 20 has beendescribed, a processing transfer apparatus for use in semiconductorprocessing equipment for processing substrates other than semiconductorwafers may also be included in the scope of the present invention. Inthis case, the substrate transfer apparatus can be generally applied tothose configured to transfer each substrate from a substrate containerto a substrate processing apparatus through an interface space in whichan atmospheric gas is properly controlled, as well as carry thesubstrate from the substrate processing apparatus to the substratecontainer through the interface space. For example, as the substrate,semiconductor substrates and glass substrates may be mentioned. Whilethe wafer has been described on the assumption that has a 300 mm size,the robot arm may be modified to have other link sizes in order to beapplied to wafers of other sizes.

In each of the embodiments described above, while the wafer transferapparatus 23 includes the aligner 56, it may includes another processingdevice than the aligner 56. This processing device is adapted to holdeach wafer in the interface space 29 and perform predetermined processesand operations. For example, as the processing device, a buffer memberadapted to hold each wafer 24 in the interface space 29 or an inspectiondevice adapted to hold the wafer in the interface space 29 and inspectit about quality and presence of defects. It should be noted that thewafer transfer apparatus 23 not including the processing device, such asthe aligner 56, may also be included in the scope of the presentinvention.

In the case where it is necessary to transfer each wafer 24 over a widerregion in the left and right directions in order to carry the wafer tothe processing device even though only three or less FOUP openers areused, the application of this invention enables advantageous wafertransfer, even with the length B in the left and right directions of theinterface space being significantly small. In this case, each positionarranged in the left and right directions relative to the pivot axis A0is determined appropriately, depending on positions of respectiveobjects to be moved in the left and right directions. In place of usingthe FOUP openers, substrate container setting tables may be provided forsetting substrate containers.

In this embodiment, while the first link member 41 a has been describedto be able to angularly displace by 90° in one and the other directionsabout the pivot axis A0 relative to the reference line P0 passingthrough the pivot axis A0 and extending in the forward and backwarddirections X, the operation of the first link member 41 a is not limitedto this mode. Additionally, in this embodiment, while the expressions ofthe forward and backward directions X, left and right directions Y andupward and downward directions Z have been used, for example, firstdirections, second directions and third directions or the like, whichare orthogonal to one another, may be employed as alternatives.

Although the invention has been described in its preferred embodimentswith a certain degree of particularity, obviously many changes andvariations are possible therein. It is therefore to be understood thatthe present invention may be practiced otherwise than as specificallydescribed herein without departing from the scope and spirit thereof.

1. A wafer transfer apparatus for transferring a semiconductor waferwhich is carried while being contained in a substrate container,relative to a wafer processing apparatus for semiconductor processing,comprising: an interface space forming portion defining an interfacespace which is to be filled with a preconditioned atmospheric gas, theinterface space forming portion having a front wall and a rear wallwhich are arranged at a predetermined interval in forward and backwarddirections, the front wall having a front opening formed therein, andthe rear wall having a rear opening formed therein; a FOUP openerconfigured to open and close the substrate container located adjacent tothe interface space and the front opening of the interface space formingportion; and a wafer carrying robot located in the interface space andconfigured to carry the semiconductor wafer between the front openingand the rear opening, wherein the wafer carrying robot includes: a basewhich is fixed to the interface space forming portion and at which apredetermined pivot axis is set; a robot arm having a proximal end and adistal end, the robot arm including a plurality of link membersconnected with one another in succession in a direction from theproximal end to the distal end, the proximal end being connected withthe base, the distal end being provided with a robot hand for holdingthe wafer, the robot arm being configured to be angularly displacedabout the pivot axis; and a drive unit configured to drive each of thelink members of the robot arm so that the link members are angularlydisplaced, individually, about each corresponding axis, wherein, in aminimum transformed state where the robot arm is transformed such that adistance defined from the pivot axis to an arm portion which is farthestin a radial direction relative to the pivot axis is minimum, a minimumrotation radius R, as the distance defined from the pivot axis to thearm portion which is the farthest in the radial direction relative tothe pivot axis, is set to exceed ½ of a length B in the forward andbackward directions of the interface space, the length B correspondingto a length between the front wall and the rear wall of the interfacespace forming portion, and is further set to be equal to or less than asubtracted value (B−L0) to be obtained by subtracting a distance L0 inthe forward and backward directions from the rear wall of the interfacespace forming portion to the pivot axis, from the length B in theforward and backward directions of the interface space (i.e.,B/2<R≦B−L0).
 2. The wafer transfer apparatus according to claim 1,wherein the minimum rotation radius R is set to be equal to or less thanan allowable length (B−L0−E) to be obtained by subtracting the distanceL0 in the forward and backward directions from the rear wall of theinterface space forming portion to the pivot axis and a length E of arobot invasion restricted region, which is set for the FOUP opener andis measured from the front wall in the forward and backward directionstoward the rear wall, from the length B in the forward and backwarddirections of the interface space (i.e., R≦B−L0−E).
 3. The wafertransfer apparatus according to claim 2, wherein the robot arm includes:a first link member which is connected at its one end with the base,configured to be angularly displaced about the pivot axis, and at whicha first joint axis is set in parallel to the pivot axis; a second linkmember which is connected at its one end with an other end of the firstlink member, configured to be angularly displaced about the first jointaxis, and at which a second pivot axis is set in parallel to the pivotaxis; and a third link member which is connected at its one end with another end of the second link member, configured to be angularlydisplaced about the second joint axis, and includes the robot hand at another end of the third link member for holding the wafer, wherein afirst link distance L1 defined as a distance from the pivot axis to anend of the first link member, which is farthest in a radial directiontoward the first joint axis relative to the pivot axis, is set to exceed½ of the allowable length (B−L0−E) and to be equal to or less than theallowable length (B−L0−E) (i.e., ((B−L0−E)/2≦L1≦B−L0−E).
 4. The wafertransfer apparatus according to claim 3, wherein a first axis-to-axisdistance L11 from the pivot axis to the first joint axis and a secondaxis-to-axis distance L12 from the first joint axis to the second jointaxis are set to be equal to each other, and wherein a second linkdistance L12 defined as a distance from the second joint axis to an endof the second link member, which is farthest in a direction toward thefirst joint axis relative to the second joint axis, is set to exceed ½of the allowable length (B−L0−E) and to be equal to or less than theallowable length (B−L0−E).
 5. The wafer transfer apparatus according toclaim 4, wherein a third link distance L3 defined as a distance from thesecond joint axis to an end of the third link member or a portion of thewafer, which is farthest in a radial direction relative to the secondjoint axis, is set to exceed ½ of the allowable length (B−L0−E) and tobe equal to or less than the allowable length (B−L0−E).
 6. The wafertransfer apparatus according to claim 5, wherein the first link distanceL1, the second link distance L2 and the third link distance L3 arerespectively set to be equal to the allowable length (B−L0−E).
 7. Thewafer transfer apparatus according to claim 1, wherein the front openingincludes four openings which are formed in the interface space formingportion, the four openings being arranged in left and right directionsorthogonal to both the forward and backward directions and a directionof the pivot axis, and wherein the FOUP opener includes four openerswhich are provided in order to open and close the four openings,respectively.
 8. A substrate transfer apparatus for transferring asubstrate, in an interface space filled with a preconditionedatmospheric gas, relative to a substrate processing apparatus forprocessing the substrate, comprising: an interface space forming portiondefining the interface space, the interface space forming portion havinga front wall and a rear wall which are arranged in predetermined forwardand backward directions at an interval, the front wall having a firsttransfer port formed therein, and the rear wall having a second transferport formed therein; an opening and closing unit configured to open andclose the first transfer port of the interface space forming portion;and a substrate carrying robot located in the interface space andconfigured to carry the substrate between the first transfer port andthe second transfer port, wherein the substrate carrying robot includes:a base which is fixed to the interface space forming portion and atwhich a predetermined pivot axis is set; a first link member which isconnected at its one end with the base, configured to be angularlydisplaced about the pivot axis, and at which a first joint axis is setin parallel to the pivot axis; a second link member which is connectedat its one end with an other end of the first link member, configured tobe angularly displaced about the first joint axis, and at which a secondpivot axis is set in parallel to the pivot axis; a third link memberwhich is connected at its one end with an other end of the second linkmember, configured to be angularly displaced about the second jointaxis, and includes a robot hand at an other end thereof for holding thesubstrate; and a drive unit configured to drive each of the link membersso that the link members are angularly displaced, individually, abouteach corresponding axis, wherein the pivot axis is located nearer therear wall than the front wall in the forward and backward directions,and wherein a first link distance L1 defined as a distance from thepivot axis to an end of the first link member, which is farthest in aradial direction toward the first joint axis relative to the pivot axis,is set to exceed ½ of a length B in the forward and backward directionsof the interface space, the length B corresponding to a length betweenthe front wall and the rear wall of the interface space forming portion,and is further set to be equal to or less than a subtracted value (B−L0)to be obtained by subtracting a distance L0 in the forward and backwarddirections from the rear wall of the interface space forming portion tothe pivot axis, from the length B in the forward and backward directionsof the interface space (i.e., B/2<L1≦B−L0).